Major retailers and suppliers are to meet the Food Standards Agency (FSA) to work out how to prevent food becoming contaminated and entering the supply chain.

The FSA ordered the meeting last week following a spate of mis-labelled or contaminated food products reaching the public.

On Sunday a company which supplied halal food found to contain traces of pork DNA was named.

Food distributor 3663 identified McColgan Quality Foods Limited, a Northern Ireland-based company, as the source of "the very small number of halal savoury beef pastry products" found to contain pork DNA which it supplied to prisons.

In a statement, 3663 confirmed that all halal products from this manufacturer have been withdrawn from supply. 3663 has not been suspended, but a "sub-contractor" has been suspended, the Ministry of Justice (MoJ) said. Islamic law forbids the consumption of pork.

Last month horse meat was found in burgers sold by a number of major supermarkets.

Environment, Food and Rural Affairs committee chairman Anne McIntosh has raised concerns that the recent cases could be just the tip of the iceberg, the BBC said, and has questioned whether the FSA is fit for purpose.

The FSA is investigating how far contaminated products have been distributed. Steve Wearne, a director at the FSA, said it called the meeting "of a range of suppliers" today to "stress again the responsibility of all food businesses to ensure the food that they sell contains what it says on the label", the BBC said.

Ms McIntosh said many questions remained unanswered, telling BBC Breakfast: "We have to ask why, so far, the FSA have not found themselves one case of cross-contamination." She said she was "shocked" to learn that burgers could have been contaminated with horse meat for a year and warned that more cases could yet come to light."

Mr Wearne said a "very thorough" investigation was under way and that the FSA was meeting retailers and suppliers "to make sure that they fully understand their responsibilities". He told BBC Breakfast: "Consumer confidence is key and we need the food industry to tell us what they are going to do to build the confidence back."